/**
 * @author ypz
 * @date 2021/9/14 16:19
 */
public class StringKnow {
    public static void main(String[] args) {
        //String 不可变
        String str = "";
        /** The value is used for character storage. */
        //private final char value[];
        //String 不可被继承 final修饰
        //线程安全
        StringBuffer sb = new StringBuffer();
        sb.append("123");
        //线程不安全
        StringBuilder sbd = new StringBuilder();
        sbd.append("123");
        sbd.append(123);
    }
}
